1. The Field of the Invention
The present invention relates to systems for heating and mixing fluids which can be used for inactivating cells or microorganisms.
2. The Relevant Technology
The biopharmaceutical industry uses a broad range of mixing systems for a variety of processes such as in the preparation of media and buffers and in the growing or processing of cells and microorganisms. Many conventional mixing systems, including bioreactors, comprise a rigid tank that can be sealed closed. A drive shaft with impeller is rotatably disposed within the tank. The impeller functions to suspend and mix the components.
In many cases, great care must be taken to sterilize and maintain the sterility of the mixing system so that the culture or other product does not become contaminated. Accordingly, between the production of different batches, the mixing tank, mixer, and all other reusable components that contact the processed material must be carefully cleaned to avoid any cross contamination. The cleaning of the structural components is labor intensive, time consuming, and costly. For example, the cleaning can require the use of chemical cleaners such as sodium hydroxide and may require steam sterilization as well. The use of chemical cleaners has the additional challenge of being relatively dangerous, and cleaning agents can be difficult and/or expensive to dispose of once used.
Once processing step commonly used with biological fluids containing a culture is to heat the fluid to a defined temperature to kill or inactivate the cells or microorganisms therein. This has historically been accomplished by heating the fluid within a stainless steel tank. Such processing, however, again requires the cleaning and sterilization of the tank between different batches.
Accordingly, what is needed in the art are system that permit controlled and uniform heating of a fluid that does not require washing or sterilization between batches and that minimizes any potential for breach in sterility.